One small practical tip with the MAX2000
May I suggest cleaning the brass thread inserts with isopropyl alcohol, I simply put some iso on a tissue and fed it in and waggled it about and it got lots of dark dirt out. I managed to get a lot of grime out of mine, virtually factory fresh. Those threads seem to have quite a bit of machine grime left in them and I think this is good for electrical contact.
I do not think it will be the difference between a working and non working antenna but low resistance and clean electrical contact has to be a good thing.
The threads now glide on as well, very smooth screw action.
Nice plots Marconi will absorb them.. seems like no radials fairs quite well. Interesting how the higher angle radiation pattern changes with and without mast isolation. (I assume ISO means mast isolated?) This was close to how I was operating a few days ago with mast about 28-30 feet 10M exactly of RG-213U coax, no radials and no isolation. It suggests there could have been CMC on mast/coax but I experienced no negative effects in operation. It makes you wonder if the CMC is actually adding something to this antenna design. I have read that lobes at high angles can increase RX noise.
This article from copper electronics is oddly enough seemingly the reverse of your plots, the caveat being they are models at only 1/2 wave above ground not 1 Lambda like your models. (60 degree nulls with the GPK installed, they are old plots though) when it comes to RX/TX of the higher angle lobes which this guy says that sky wave noise could be reduced with the standard Solarcon GPK. Suggesting and to quote: "an Imax 2000 with the GPK installed will likely experience the 'noise floor' reduced by as much as 12 dB. "
http://www.copperelectronics.com/discus4/messages/7750/20506.html?1023340740
I was very happy with the results using the IMAX and at the moment the differences between the Max2000 and the Gain Master appear very difficult to feel in operation at least on line of sight contacts. Maybe the GM might have a tiny extra bit of poke right down at the horizon but it is rather impossible to know this. I have to go on gut operational feeling rather than scientific measurements. They both work for me. Both good antennas without the complication of cumbersome ground plane radials which is advantageous for static mobile temporary installs.
